The 1987 market crash that prompted Alan Greenspan's first statement as Federal Reserve chair was Black Monday.
Black Monday refers to October 19, 1987, when stock markets around the world collapsed. The Dow Jones Industrial Average fell 22.6% in one session, its largest one-day percentage decline. Alan Greenspan had become chair of the U.S. Federal Reserve only months earlier, and the central bank quickly announced its readiness to provide liquidity to the financial system.
Concerns about overvaluation, rising interest rates, trade tensions, and automated portfolio-insurance strategies contributed to the panic. The crash exposed how trading technology and linked international markets could transmit selling pressure rapidly.
The Federal Reserve response helped reassure banks and markets, and the crash did not produce a depression like the 1929 collapse. “Black Tuesday” is associated with October 29, 1929, while Black Monday in this context specifically means October 19, 1987.